184 AGRICULTURAL EXPERIMENT STATION. [Jan. 



1. Field Experiments carried on for the Purpose of 



ASCERTAINING THE EfFECT OF THE EXCLUSION OF 



Every Form of Nitrogen-containing Manurial 

 Matter From the Fertilizer applied for the 

 Production of Oats on the Yield, as compared 

 with the Results obtained when a Liberal 

 Amount of Various Nitrogen-containing Manu- 

 rial Substances is applied under Otherwise Cor- 

 responding Circumstances for the Same Purpose. 



Field A. 



The unbroken record of this field extends over more than 

 twenty years. The systematic treatment of the soil, as far 

 as suitable modes of cultivation and of manuring are con- 

 cerned, was introduced durino; the season of 1883-84. The 

 subdivision of the entire area into eleven plats (one-eighth 

 of an acre each), of a uniform size and shape, one hundred 

 and thirty feet long and thirty feet wide, with an unoccupied 

 and unmanured space of five feet in width between adjoining 

 plats, has been retained unaltered since 1884. A detailed 

 statement of the particular aim and general management of 

 our experiments, as well as of the results obtained in that 

 connection from year to year, forms a prominent part of our 

 contemporary printed annual reports, to which I have to 

 refer for details. 



Since 1889 the main object of observations iqjon the same 

 field has been to studi/ the influence of an entire exclusion 

 of any additional nitrogen-containing manurial substance 

 from the soil wider cultivation, as ivell as of a definite 

 additional supply of nitrogen in difierent forms of cotnbi- 

 nation, on the character and yield of the crop selected for the 

 trial. The treatment of the soil adopted in preceding years 

 favored this new project for field observations, as may be 

 noticed from the following remarks. 



Several plats which for five preceding years did not receive 

 any nitrogen compound for manurial purposes were retained 

 in that state, to study the efl'ect of an entire exclusion of 

 nitroffen-containing manurial substances on the crop under 



